Session: Poster Session: Enterococci/URE
Monday, October 27, 2008: 12:00 AM
Room: Hall C
Background: Quinupristin-dalfopristin(Q-D) and linezolid have been widely used in the treatment of vancomycin-resistance Enterococcus faecium (VREF) infections. Recently, increasing resistance of VREF to these antibiotics is concerning. We analyzed all episodes of VREF bacteremia occurring in Asan Medical Center to compare the efficacy and incidence of development of in vitro resistance to these two antibiotics. Methods: The records of all the patients who had blood cultures positive for VREF between January 2003 and June 2007 were investigated. The records of those patients who were older than 16 years of age, had clinically significant VREF bacteremia, and received adequate Q-D or linezolid treatment, were fully reviewed. Results: A total of 136 patients were enrolled who received an adequate antibiotic for VREF bacteremia during study period. Sixty patients received Q-D and 76 received linezolid. There were no significant differences between two groups in the characteristics of patients. There were no differences in 30-day mortality after bacteremia (28/60, 46.7% in Q-D group vs 30/76, 39.5% in linezolid group, P = 0.40), clinical response (32/60, 53.3% vs 48/76, 63.2%, P = 0.25) and microbiological response (34/60, 56.7% vs 52/76, 68.4%, P = 0.16) in all-treated patients, and relapse of bacteremia (2/22, 9.1% vs. 3/33, 9.1%) between two study groups. However, the incidence of development of in vitro resistance to Q-D in VREF clinical isolates was 27.5% (14/51, 5 in blood, 7 in stool, 2 in drainage specimens) which was higher than that of linezolid (1.5% , 1/65 in stool, P < 0.01). Conclusions: There was no significant difference in efficacy between Q-D and linezolid in the treatment of VREF bacteremia. However, the incidence of development of in vitro resistance was significantly higher in Q-D group than in linezolid group.